The use of medical consumables plays an essential role in the field of medicine and medical technology. Thus, for example, medical instruments are often used in medical diagnostics and analysis, and in medical therapeutics, and these instruments often have e.g. a diagnostic, analytic or therapeutic function, or combinations of these functions, and require one or more medical consumables to carry out this function. The medical consumables and the medical instrument together form a medical system. Here the medical consumables need not necessarily be physically connected to the medical instrument.
Examples of such medical systems and medical instruments include medical analysis instruments, which are used for quantitative and/or qualitative detection of at least one analyte in a sample, for example for detecting one or more metabolites in a bodily fluid. As an exemplary application, reference is made here to glucose measuring instruments for determining a glucose content in a bodily fluid, for example in blood, interstitial fluid, saliva or urine. Such analysis instruments, or other analysis instruments, generally use one or more test elements, which can be used for the quantitative and/or qualitative detection of the analyte. By way of example, these test elements can comprise one or more test fields, which carry out a specific reaction that can be detected by chemical or physical means when they come into contact with the analyte, or which test fields experience a specific, measurable change. Accordingly, the analysis instruments can be designed to determine the analyte concentration qualitatively and/or quantitatively in an optical, electrochemical or other fashion by using the test elements. By way of example, the test elements can be available as test tubes, test strips, test tapes, test wheels with test fields arranged on an upper side and/or on a circumference, foldable test papers with a plurality of test fields, or else in a different form. Here, the test elements can be available individually or else, for example, in large numbers in one or more magazines, wherein, in the latter case, the magazine itself can also be embodied as a consumable.
Lancet systems are another example of such medical systems with consumables; here a piercing aid for example acts as a medical instrument. This piercing aid is generally designed to perforate a skin section of a patient by means of one or more consumables in the form of lancets, for example in order to produce a sample of blood or interstitial fluid.
Medication systems with metering devices are further examples of medical systems, medical instruments and medical consumables. Such metering devices generally interact with at least one medical consumable or even with many types of medical consumables. Thus, for example, cartridges or other storage vessels of medicament can be used, which are metered by means of the metering device. In this case, the medicament itself and/or the medicament with the corresponding vessel (e.g. the cartridge) can be considered to be a consumable. Medication pumps, for example insulin pumps, are examples of such metering devices. However, these metering devices generally also require further types of medical consumables, more particularly catheters or similar medical consumables.
Many further types of medical systems of this type, with a medical instrument and at least one consumable, are known. Here, the consumables can also be present in combination, and so one or more consumables of one variety can also be connected to one or more consumables at least of a further variety. Medical consumables can be available individually or else as a magazine of individual elements.
In practice, a challenge for such medical systems consists of the fact that the medical instrument, in order to carry out the medical function thereof, requires information, which can change, in order to be able to interact correctly with the consumable. Thus, for example, the test elements can differ between batches, and so batch-specific information can be required for the correct evaluation of the quantitative and/or qualitative detection of the at least one analyte in the sample. By way of example, this can be or contain an item of information relating to how the optical luminescence or absorption properties, i.e. the luminescence and/or color of a test field on a test element, changes with the analyte concentration. Alternatively, or in addition thereto, this can also include electrochemical evaluation information. Here, for example, current profiles and/or electric potentials are measured.
By way of example, in the case of lancet systems, for example lancet systems with consumables in the form of a lancet magazine with a plurality of lancets or in the form of an individual lancet, a piercing aid can require information in respect of whether a legitimate type of consumable was inserted into the piercing aid, for example a lancet from a legitimate producer or of the legitimate type. In general, such information in this type of consumable or in other types of consumables can for example also be used for fraud prevention, in order to distinguish between articles from a legitimate or authorized producer and “faked” consumables. In addition to avoiding economic damages, the latter can greatly reduce the risk of health-related damages from faked medical products.
In the case of medical systems with at least one therapeutic function, for example a medication function, too, the medical instrument generally requires specific information for the correct interaction with the at least one medical consumable. By way of example, in the case of medical systems with at least one metering device, for example insulin pumps, information in respect of the type and/or the content of a cartridge of a medicament can be required. If use is made of consumables such as catheters and/or cannulae in order to meter the medicament, e.g. a filling volume of such a consumable, e.g. a filling volume of the catheter, can be necessary for ensuring correct initial filling or priming of the catheter.
These are merely a few examples of information that can or must be interchanged in such medical systems. There are various options in the prior art for solving this problem.
By way of example, a first option consists of realizing the information by entering a code number or a similar code into the medical instrument of the medical system. However, here a user is subjected to the necessity of undertaking an additional operative action that has to be carried out correctly. This can lead to an incorrect association between the code and the utilized consumable. Furthermore, the utilized code has the lowest information density and therefore generally does not contain comprehensive information in respect of the properties of the utilized consumable.
Furthermore, there is the option of attaching an information carrier to each batch of new consumables, for example each batch of new test elements; by way of example, this is implemented in conventional glucose measuring instruments. By way of example, this can be a so-called ROM key, which can, for example, be added to each pack. The user is required to enter this ROM key into the analysis instrument before using the new batch such that the correct information can be used for evaluating the measurement. An advantage of this technique consists of the fact that there can be a relatively high information density. However, since the ROM key must be used as an additional data carrier, this method is generally not very cost effective. Moreover, this method also once again asks for an additional operative action by the user, and it is not possible to ensure a unique association with the utilized consumable. There is a risk, particularly in the case of elderly patients or children, that the ROM key is not replaced when a new batch of e.g. test strips is used. Since this can lead to incorrect measurement results being output, this can have consequences in respect of erroneous medication based on the incorrect measurement results.
Thus, the prior art has also disclosed various medical systems in which such an information carrier is provided directly on the consumable; i.e. it is not provided as a separate information carrier but fixedly connected to the consumable. Since these information carriers have to be designed cost effectively owing to ever increasing cost pressures in the medical field and moreover must have a very small design, known electronic information carriers such as radiofrequency labels cannot be used in many cases, at least as long as the production costs of such electronic information carriers still form a significant proportion of the overall costs of the consumable.
Thus, medical systems are known, in which two-dimensional or three-dimensional optical codes are applied to medical consumables and these can be read by a corresponding optical code reader of the medical instrument. By way of example, such systems are described in U.S. Pat. No. 6,588,670 B2. U.S. Pat. No. 4,476,149 and U.S. Pat. No. 6,168,957 also describe test strips, which are equipped with appropriate barcodes as optical codes. Reference to such optical codes can be made in an exemplary manner in the following text.
Thus, U.S. Pat. No. 4,476,149 for example describes a characterization of a consumable by means of a low-density barcode, which can be read out longitudinally. Provided that the barcode is applied directly onto the consumable and read out at the instant that the analysis or insertion method is activated, this ensures a reliable association with the consumable. The consumable itself, together with the optical code, constitutes the data carrier. However, reading a longitudinal barcode is not without problems in practice. Since a manual pulling-through method, in which the consumable in the form of a test strip is guided through the barcode reader, is not very reliable despite the specific properties of modern one-dimensional barcodes, the consumable must in general be read out in a motorized fashion. To this end, the shape of the consumable must also be limited somehow so that it can be drawn into the medical instrument. Moreover, the barcode only permits low to medium information densities. U.S. Pat. No. 6,588,670 B2 has disclosed the characterization of a consumable by means of a low-density one-dimensional barcode using a scanner integrated into the medical instrument. In this case, the barcode is on the consumable, which, although it reduces an association problem, also requires the user here to scan the consumable by means of an additional operative action.
U.S. Pat. No. 6,168,957 has disclosed a characterization by means of color information, the spectrum of which is determined. Here color information applied to the consumable is used as a reference and hence as an information carrier. However, as a result of technical limitations and the principle involved, the information content of such color information generally is comparatively low.